Galopin pursued a career in business became in 1913 managing director of Fabrique national d'armes de guerre at Herstal which had originated as a manufacturer of firearms.

In 1935 he became governor of the Société Générale de Belgique (SGB), a giant holding company with close ties to the Belgian government which dominated the economy of Belgium and its colonial empire and controlled almost 40 percent of the country's industrial production.

[3][4][5] It served as a sort of a Belgian shadow government in the occupied territory that decided a common stance on economic and social issues and was able to set rules for dealing with the German administration.

The committee included politicians and businessmen: Because of his power and influence within the Belgian wartime economy, Galopin was nicknamed "the Uncrowned King of Belgium" by German occupation officials.

[9] After some initial acceptance, in 1941 and 1942, German officers began to force Belgian businessmen to disapply the distinction at the risk of personal punishment and the confiscation of their businesses.

[12] Galopin was assassinated in 1944 by members of Devlag, a radical pro-Nazi paramilitary group active in Flanders, under direct orders from Robert Jan Verbelen.